The subject matter disclosed herein relates to gas turbine transition pieces and, more specifically, to aft frame assemblies with cooling channels for gas turbine transition pieces.
Turbine components, such as buckets (blades), nozzles (vanes), transition pieces, and other hot gas path components of industrial and aircraft gas turbine engines, may be formed of nickel, cobalt or iron-base superalloys with suitable mechanical and environmental properties for turbine operating temperatures and conditions. Because the efficiency of a turbomachine is partially dependent on its operating temperatures, there may be a demand for components such as turbine buckets, nozzles and transition pieces to be capable of withstanding increasingly higher temperatures. As the maximum local temperature of a superalloy component approaches the melting temperature of the superalloy, forced air cooling may be utilized to partially cool the component. For this reason, compressor discharge air may be forced through internal cooling holes within aft frame assemblies for transition pieces then discharged internally therein to transfer heat from the component. Cooling holes can also be configured so that cooling air serves to film cool the surrounding surface of the component.
However, the machining of cooling holes in relatively small spaces (such as aft frame assemblies) may be limited. Furthermore, cooling holes may require additional compressor discharge air to cool the component due to the limited distribution of a straight-passage cooling hole arrangement.
Accordingly, alternative aft frame assemblies with cooling channels would be welcome in the art.